Merge "Revert "Remove cutils threads.h header completely."" into main am: ef2cae13

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2712413



Change-Id: I2d3c1dd6bdb4e2f2cc34d68204eecb5ec923dfe7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>